You're planning a trip with Southwest Airlines, and you're wondering, just how big can your carry-on be? You're not alone! This is one of the most common questions travelers have, and getting it right can save you a lot of hassle (and money!) at the airport. Let's dive deep into Southwest's carry-on policy, step-by-step, to make sure you're fully prepared for your flight.
Understanding Southwest Airlines Carry-On Policy: A Comprehensive Guide
Southwest Airlines has always been known for its customer-friendly policies, and while some aspects have changed recently (like the "Bags Fly Free" policy for checked luggage for most passengers as of May 28, 2025 bookings), their carry-on rules remain quite generous. The key is knowing the precise dimensions and what counts as a "personal item."
Step 1: Let's Start with the Basics – Your Two Free Carry-On Items!
Did you know Southwest allows you to bring two items onto the plane for free? That's right! This includes one standard carry-on bag and one smaller personal item. This is a big advantage compared to some other airlines that might charge for a carry-on or only allow a personal item.
Sub-heading: What Qualifies as a Carry-On Bag?
Your main carry-on bag is the one that goes in the overhead bin. Southwest is pretty specific about its dimensions.
Dimensions: Your carry-on bag must not exceed 24 inches (L) x 16 inches (W) x 10 inches (H). This measurement includes wheels and handles. It's crucial to measure your bag accurately before you leave for the airport. Don't just eyeball it! A small difference can lead to your bag being gate-checked, which can be inconvenient.
Weight Limit: Southwest does not have a specified weight limit for carry-on bags. The general rule is that you must be able to safely lift your bag into the overhead bin without assistance. If you struggle to lift it, airline staff might ask you to check it.
Sub-heading: What Qualifies as a Personal Item?
Your personal item is the smaller bag that must fit under the seat in front of you. This is where many people get confused or try to push the limits.
Dimensions: Your personal item should not exceed 18.5 inches (L) x 13.5 inches (W) x 8.5 inches (H).
Examples of Personal Items: Common personal items include:
A purse
A briefcase
A laptop bag
A small backpack
A camera bag
A pillow (though it might still count towards your allowance)
Remember, your pet carrier, if you're traveling with a small domesticated cat or dog, will count as one of your carry-on items (specifically, the personal item). A fee of $125 (one-way) is levied for each pet carrier.
Step 2: Measuring Your Bags - The Most Crucial Step!
This cannot be stressed enough. Before you even think about packing, measure your bags!
Sub-heading: How to Measure Properly
Empty Your Bag (or simulate fullness): While you might measure an empty bag, it's best to measure it when it's packed as you intend to travel. A soft-sided bag can expand, and what fit when empty might not when full.
Include All Protrusions: This is key! Measure from the outermost edges of your bag, which means including:
Wheels: Those little wheels add a couple of inches!
Handles: When extended or retracted, make sure to account for their full dimensions.
Side Pockets/Attachments: Anything that sticks out from the main body of the bag.
Use a Tape Measure: Don't guess. Use a flexible tape measure to get accurate length, width, and height.
Sub-heading: Why Measuring Matters
Avoid Gate-Checking: If your carry-on is deemed too large at the gate, you'll be required to gate-check it. This means it will be taken from you right before you board and put in the cargo hold. While not the end of the world, it can be inconvenient and cause delays.
Prevent Fees (for checked bags): With Southwest's new checked baggage policy for most fares booked from May 28, 2025, if your carry-on is oversized and you have to check it, you might incur a checked baggage fee.
Smooth Boarding: Having your bags correctly sized ensures a quicker and smoother boarding process for everyone.
Step 3: Packing Smart - Maximizing Your Carry-On Space
Once you know your bag dimensions, it's time to pack efficiently.
Sub-heading: Tips for Your Main Carry-On
Roll, Don't Fold: Rolling clothes often saves space and helps reduce wrinkles.
Use Packing Cubes: These are a game-changer! They compress your clothes and keep your bag organized, making it easier to find things and fit more.
Wear Your Bulkiest Items: If you have a heavy coat or bulky shoes, wear them on the plane instead of packing them.
Utilize Every Inch: Stuff socks into shoes, use small gaps for chargers or toiletries.
Liquids, Aerosols, and Gels (LAGs): Remember the TSA's 3-1-1 rule:
Containers must be 3.4 ounces (100 milliliters) or less per item.
All LAGs must fit comfortably in one quart-sized, clear, sealable plastic bag.
Each passenger is limited to one such bag.
Sub-heading: Tips for Your Personal Item
Essentials Only: This is for items you'll need during the flight or immediately after landing. Think medications, important documents, electronics, a book, snacks, etc.
Easy Access: Pack items you'll need quickly at the top.
Maximize Under-Seat Space: Choose a soft-sided bag for your personal item if possible, as it can be more forgiving and easier to squish into the under-seat area.
Step 4: Special Items and Exceptions
Southwest is generally accommodating, but some items have specific rules.
Sub-heading: Assistive Devices and Medical Equipment
Assistive and mobility devices (like walking canes, wheelchairs, and crutches) generally do not count towards your carry-on limit.
Medications (including insulin kits, EpiPens, and over-the-counter medications) are typically allowed, and liquid medications in containers larger than 3.4 oz may be permitted with a doctor's note and proper screening.
Breast pumps and breast milk are also allowed in addition to your standard carry-on allowance.
Sub-heading: Musical Instruments
If your instrument (including its case) is within the standard carry-on dimensions (24" x 16" x 10"), you can bring it as your carry-on if there's space.
If it exceeds those dimensions, it might still be allowed onboard if it fits in an overhead bin or under a seat and space is available.
For larger instruments that don't fit, you can purchase a separate seat for them. It must be secured with a seatbelt in the first row, near the window, and not block any signage. Instruments like double basses or cellos might need to be checked.
Sub-heading: Sports Equipment
Most sports equipment will need to be checked baggage. Southwest generally allows sports equipment to be checked as part of your standard baggage allowance, provided it meets the size and weight limits for checked bags (which are generally 50 lbs and 62 inches total linear dimensions).
Oversized or overweight fees may apply if your sports equipment exceeds these limits. For example, a surfboard typically incurs a fee, unless it's a Hawaiian inter-island flight where it can substitute a free checked bag.
Step 5: What to Do if Your Bag is Too Big
Even with careful planning, sometimes things happen.
Sub-heading: At the Check-in Counter
If you're unsure about your bag size, you can always ask a Southwest agent at the check-in counter before you head to security. They might have a sizing template, and it's better to address any issues here than at the gate.
Sub-heading: At the Gate
If your carry-on is deemed too large at the boarding gate, the airline staff will require you to gate-check it. This means the bag will be tagged and sent to the cargo hold, and you'll pick it up at the baggage claim carousel at your destination. This is often done at no additional charge for carry-ons that simply don't fit in the overhead bin, but it can cause a slight delay in your journey. Be prepared for this possibility by keeping any essential items (medication, passport, wallet, etc.) in your personal item.
Frequently Asked Questions (FAQs)
Here are 10 common questions about Southwest Airlines carry-on policies, starting with "How to," and their quick answers:
How to determine if my carry-on bag is too big for Southwest Airlines? Measure your bag including wheels and handles. If it exceeds 24 inches (L) x 16 inches (W) x 10 inches (H), it is too big for the overhead bin.
How to measure my personal item for Southwest Airlines? Measure your personal item including any protrusions. It should not exceed 18.5 inches (L) x 13.5 inches (W) x 8.5 inches (H) to fit under the seat in front of you.
How to pack liquids in my Southwest carry-on? Follow the TSA 3-1-1 rule: containers must be 3.4 oz (100 mL) or less, fit in one quart-sized clear plastic bag, and each passenger is limited to one bag.
How to travel with a musical instrument on Southwest Airlines? Small instruments within carry-on dimensions can be brought onboard. Larger ones may be allowed if they fit in the overhead bin or under a seat, or you can purchase a separate seat for them.
How to handle an oversized carry-on at the Southwest gate? If your carry-on is deemed too large at the gate, it will likely be gate-checked and you'll retrieve it at baggage claim upon arrival.
How to bring a pet carrier as a carry-on on Southwest Airlines? A pet carrier (for small domesticated cats or dogs) counts as your personal item and must fit under the seat. A one-way fee of $125 applies.
How to ensure my carry-on fits in the overhead bin? Always measure your bag accurately, including wheels and handles, to ensure it's within Southwest's 24" x 16" x 10" limit. Pack efficiently to avoid overstuffing.
How to pack extra items like coats or umbrellas on Southwest? Additional items like coats, wraps, and umbrellas typically do not count against your carry-on or personal item allowance.
How to know if there's a weight limit for Southwest carry-ons? Southwest Airlines does not have a specific weight limit for carry-on bags, but you must be able to lift it into the overhead bin unassisted.
How to manage medications in my Southwest carry-on? Liquid medications exceeding 3.4 oz are generally allowed but should be declared to TSA for screening. Prescription and over-the-counter medications are permitted.
